This invention generally relates to the art of electrical connectors and, particularly, to connectors for electrically interconnecting flat flexible circuitry.
A flat flexible circuit conventionally includes an elongated flat flexible dielectric substrate having laterally spaced strips or conductors on one or both sides thereof. The conductors may be covered with a thin, flexible protective layer on one or both sides of the circuit. If protective layers are used, cutouts are formed therein to expose the underlying conductors at desired contact locations where the conductors are to engage the conductors of a complementary mating connecting device which may be a second flat flexible circuit, a printed circuit board, discrete electrical wires or the terminals of a mating connector.
A wide variety of connectors have been designed over the years for terminating or interconnecting flat flexible circuits with complementary mating connecting devices. Major problems continued to plague such connectors, particularly in the area of cost and reliability. Not only is the direct material costs of such connectors unduly high, but an undue amount of labor time is required in assembling such connectors. These problems have been solved by providing simple, inexpensive and reliable connector structures which do not use conductive terminals, such as those shown in U.S. Pat. Nos. 6,039,600 and 6,077,124 which are assigned to the assignee of the present invention.
The connector structures shown in the above-identified patents and other prior art use various forms of body members about which a flat flexible circuit is wrapped, with the conductors of the circuit facing away from the body member. Typically, the body member is generally flat or planar, and the conductors of the flat flexible circuit are biased into engagement with mating conductors in a direction generally perpendicular to the plane of the body member. This type of system requires structure which increases the thickness of the body member in order to effect the perpendicular connection. Improvements in such systems are shown in co-pending application Ser. No. 09/737,265, filed Dec. 13, 2000 and assigned to the assignee of the present invention. As shown therein, the connector for a flat flexible circuit has a relatively thin or low profile, because the flat flexible circuit is wrapped about an edge of a male body member, and the mating conductors engage the flexible circuit at the edge of the male body member in a direction generally parallel to the plane of the body member. The present invention is directed to further improvements in such systems by providing a connector assembly with means for increasing the mating forces on the conductors at the edge of the male body member.
An object, therefore, of the invention is to provide a new and improved connector assembly for flat flexible circuitry.
In the exemplary embodiment of the invention, the connector assembly is provided for interconnecting first conductors of a flat flexible circuit to a plurality of second conductors without the use of conductive terminals. The assembly includes an adapter for mating with a complementary connecting device having the plurality of second conductors thereon. The adapter includes a receptacle. A relatively rigid male body member has an edge about which the flat flexible circuit is wrapped, with the first conductors facing away from the body member at the edge thereof. The male body member is insertable into the receptacle of the adapter. A spring member is mounted on the male body member for biasing the body member in a mating direction relative to the adapter. A cam member is operatively associated between the male body member and the adapter and is movable between an inoperative position and an operative position. The cam member includes a cam surface engageable with the spring member for loading the spring member in response to movement of the cam member to its operative position.
According to one aspect of the invention, the cam member is rotatably mounted on one of the adapter or male body member and is movable relative thereto in the mating direction. The cam member includes an arcuate cam surface defining the cam surface engageable with the spring member. The spring member includes an elongated rigid portion extending transversely of the mating direction and engageable with a transverse shoulder on the male body member. An elongated leaf spring portion is connected at opposite ends thereof with the elongated rigid portion generally at opposite ends thereof.
According to another aspect of the invention, the rotatable cam member includes a cam groove. With the cam member rotatably mounted on one of the adapter or male body member, the other of the adapter or male body member includes a cam follower projection to be engaged by the cam groove. The arcuate cam surface on the cam member is eccentric relative to the axis of rotation of the cam member.
According to a further aspect of the invention, the cam member includes a first level annular peripheral portion seated in an annular recess in the male body member. The first level peripheral portion of the cam member defines the arcuate cam surface engageable with the spring member. A second level portion of the cam member includes interengagement means with the adapter when the cam member is in its operative position.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.